Release mechanism for back rest support

ABSTRACT

A wheeled stretcher or the like has an end portion hinged for movement to one or more adjusted Fowler positions, the height being determined by the location of a brace, pivotally connected adjacent the middle of the hinged portion and having a lower end engageable with one or more stops at selected distances from the hinge. The release mechanism comprises means for lifting said lower end of the brace to disengage it from the stop, and the mechanism is preferably biased toward release position and held in the &#39;&#39;&#39;&#39;stop&#39;&#39;&#39;&#39; position by a manually releasable latch.

United States Patent [191 Smith RELEASE MECHANISM FOR BACK REST SUPPORT Inventor: David J. Smith, Billerica, Mass. Assignee: C. R. Ba rd, Inc., Murray Hill, NJ. Filed: Aug. 2], 1972 Appl. No.: 282,087

US. Cl. 5/74, 5/68, 5/327 R,

. 297/377 Int. Cl A6lg 7/10, A47c 7/02 Field of Search 5/68, 70-74,

References Cited UNITED STATES PATENTS Martin 5/74 Schnaitter 5/71 Apr. 2, 1974 l,()36,026 8/1912 Temple 5/74 Primary ExaminerCasmir A. Nunberg Attorney, Agent, or Firm-C. E. Martino, Jr.

[57] ABSTRACT A wheeled stretcher or the like has an end portion hinged for movement to one or more adjusted Fowler positions, the height being determined by the location of a brace, pivotally'connected adjacent the middle of the hinged portion and having a lower end engageable with one or more stops at selected distances from the hinge. The release mechanism comprises means for lifting said lower end of the brace to disengage it from the stop, and the mechanism is preferably biased toward release position and held in the stop position by a manually releasable latch.

11 Claims, 4 Drawing Figures PATENTEU APR 2 I974 SHEET 1 BF 2 FIG. 1

1 RELEASE MECHANISM FOR BACK REST SUPPORT It has long been customary to arrange the back rest portion to body-supporting furniture so that it can be moved from horizontal(or substantially so) to more or less upright positions by hinging such back rests to a lower portion and by providing a brace or strut, the

lower end of which can be engaged with one or more stops on the fixed frame of the furniture, the spacing of such stops from the hingebeing determinative of the angle at which the back rest is held. To release the strut for changing the back rest angle it is normally necessary to lift'the back rest, releasing-the strut from its stop, and then to swing the strut to a new adjusted position, this operation requiring the use of both hands and some strength and dexterity.

According to the present invention, the stops are associated with amovable release bar, spring-biased toward a position where it prevents engagement of the strut with any of the stops, and arranged to be held releasably in its inactive position by a catch which can readily be released by one .hand. The stops are shown as serrations in the edges of a horizontally disposed channel member and the release bar is an inverted smaller channel member longitudinally slidable in the first member and provided with laterally projecting lugs engaged in slanting slots so that the release bar can move only between an inactive position, permitting engagement of the strut with any selected pair of serrations, and a release position, where it prevents such engagement.

A practical embodiment of the invention is shown in the accompanying drawing, wherein:

FIG. 1 represents a side view, in perspective, of the body-supporting part of a wheeled stretcher, with the back rest portion held in a typical Fowler position;

FIG. 2 represents a detail perspective view of the back rest, strut, stops and part of the stretcher frame with the back rest raised;

FIG. 3 represents a detail perspective view of the stops and release bar with the strut engaged, and

FIG. 4 represents a view similar to FIG. 3 with the release bar in release position.

Referring to the drawings, a typical wheeled stretcher includes a rectangular metal frame 10, a main mattress portion 11 fixed to the frame, and a back rest portion 12, having a frame 13 hinged to the main frame as indicated conventionally at 14. The safety side rails 15, shown in FIG. 1, are omitted from FIG. 2 for clarity of illustration. The back rest 12 is provided with a strut 16 of U form having its ends pivotally engaged in each side of the frame 13 as shown at 17.

The stop member is in the form of a channel 18 fixed at one end to an end 19 of the main frame 10 and having its other end fixed to a cross bar (not shown) extending across the width of the frame 10 at any convenient point more or less midway of its length. The channel 18 may be additionally braced by cross bars 20 (FIG. 2) connecting it to the sides of the frame 10. The free upper edges of the channel 18 are serrated along part of their length to provide pairs of stops 2], 21 against which the strut 16 can be selectively engaged in order to support the back rest frame 13 at various ele- Vated angles, as desired.

The release bar 22 is an inverted channel, adapted to fit freely between the serrated sides of the channel 18 and extending from a point adjacent the frame end 19 to a point beyond the innermost pair of serrations. The

side walls 23 of the release bar have a height somewhat less than the distance from the bottom of the serrations to the bottom of the channel. Pairs of laterally projecting lugs 24,24 project from the side walls 23 and pass through pairs of slanting slots 25,25 in the side walls of the channel 18 adjacent the inner and outer ends of the serrated portion. A spring 26 under tension is attached to the inner end 27 of the release bar and to a fixed point (not shown) adjacent the inner end of the channel 18. At the head end of said channel there are laterally projecting flanges 28,29. A latch lever 30 is pivoted at 31 on the flange 28 and is guided by a screw 32 in the other flange 29 engaged in the elongated slot 33 in the lever. A latch block 34 projects inwardly from the lever in a position to fit over the head end of the release bar when it is in its lowest, outermost position (FIGS. 1, 2 and 3) and a small spring 35 urges the latch lever and block into bar-engaging position (FIG. 3).

In operation, assembing the back rest 12 to be in the position of FIGS. 1 or 2, if it is desired to move the back rest to another position, including horizontal, the operator retracts the latch lever and block 30, 34 to free the end of the release bar and then makes use of both hands to apply a lifting force to the back rest. As the downward pressure on the strut 16 is relieved, the spring 26 draws the release bar inward from the position of FIG. 3 to the position of FIG. 4, bringing its flat surface to a level just above the peaks of the stops 21. This upward movement of the release bar results from its being pulled inwardly while th lugs 24, 24 move from the outer, lower, ends of their slots 25,25 to the upper, inner, ends thereof, the lugs and slots constituting cams for controlling the movement of the release bar. When the release bar is raised, the strut 16 is lifted out of engagement with the stops 21 and is free to slide in either direction (corresponding to raising or lowering the back rest) until such time as the operator may pull the release bar out and down to its latched position.

The steps 21,21 may suitably be of saw-tooth form so that the strut 16 can be advanced from lower to higher back rest positions merely by lifting the back rest and permitting the strut to fall by gravity into each successive space between stops, but the highest position is determined by the square notches 36, at the inner end of the serrated area, beyond which the strut should not be moved. At the head end of channel 18 its sides are cut away as shown at 37 to provide a space in which the strut may rest when the back rest is horizontal, particularly when the release bar is latched in its lower position. When the back rest is lowered into this space it automatically resets the release bar by pushing it down to its latched position.

The elements 18 and 22 are shown anddescribed as being channels but it is apparent that other shapes, either straight or curved, could be substituted, with suitable coordination.

It will be understood that various changes may be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of the invention and hence I do not intend to be limited to the details shown or described herein except as the same are included in the claims or may be required by disclosures of the prior art.

What I claim is:

l. A body supporting device including a horizontally hinged portion, supporting means pivotally engaging said hinged portion, at least one relatively fixed stop for holding the supporting means in a position such that the hinged portion is in an elevated position, release means movable between selected positions respectively permitting and preventing engagement of the supporting means with the stop, means normally effective for biasing said release means toward said engagementpreventing position and releasable means for overriding said biasing means and normally holding the release means in said engagement-permitting position.

2. A body supporting device according to claim 1 in which the supporting means is a strut and there are a plurality of said stops for holding the strut in a plurality of positions, and in which the release means is elongated and in said engagement-permitting position permits engagement of the strut with any selected stop and, in said engagement-preventing position, prevents engagement of the strut with all of the stops.

3. A body supporting device according to claim 1 in which there are a plurality of stops constituted by pairs of serrations in the sides of a fixed upwardly open channel, in which the release means is an elongated member longitudinally movable in said channel, and which includes cam elements in the form of lugs and grooves interconnecting said release means with said channel so that upon release of said overriding means said biasing means is effective to move said member longitudinally in a first direction to prevent the engagement of said supporting means with all of said serrations.

4. A body supporting device according to claim 3 in which the biasing means is a spring under tension.

5. A body supporting device according to claim 2 in which the biasing means is a spring under tension urging the release means toward the engagementprevention position thereof, and the releasable means is a manually operable latch operable to hold the release means in its engagement-permitting position.

6. A body supporting device comprising a main frame, a back rest horizontally hinged to said main frame, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and a head end thereof, at least one upwardly projecting stop engageable with the strut, a bar having a generally horizontal surface movable into a position between said strut and said stop to prevent engagement of the strut with the stop, means for biasing said bar into said position and a manually releasable latch for holding the bar out of said position and selectively releasing said bar for movement into said position so that upon lowering of the position of the back rest said strut slides along said bar out of engagement with said stop.

7. A device for supporting a body in a plurality of positions, one of said positions being generally horizontal, said device being according to claim 1, in which said supporting means is movable into a given plane defined by the hinged portion when said hinged portion is in a first position for supporting said body in said horizontal 4 position, said supporting means in said given plane being effective to override said biasing means and condition said releasable means for overriding the biasing means upon movement of said hinged means out of said first position.

8. A body supporting device having a main frame and including a horizontally hinged back rest, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and the head end thereof, a plurality of upwardly projecting stops constituted by pairs of serrations in the sides of an upwardly open channel fixed to the head end of the main frame, said stops being engageable with the bottom of the strut and fixed to the main frame at a point corresponding with an elevated position of the back rest, release means including an elongated member longitudinally moveable in said channel, said member being moveable between positions permitting and preventing engagement of the strut with the stops, means for biasing said release means toward said engagementpreventing position, releasable means adapted to hold the release means in said engagement-permitting position, and cam elements interconnecting said release means with said channel.

9. A body supporting device according to claim 8 in which the cam elements are laterally disposed lugs and slots which are angled away from horizontal, the lugs being engaged in the slots.

10. A body supporting device according to claim 8 in which the cam elements are lugs projecting laterally from the release means and slots in the sides of the channel, the slots being angled upwardly in the direction away from the head end of the frame and the lugs being engaged in the slots.

11. A release mechanism for an arm of a back rest of a body supporting structure, said back rest being hingedly connected at one end thereof to said structure and having an opposite end facing the head of said structure, said mechanism comprising:

a bar having a flat surface, said bar being movable relative to said structure into first and second positions;

biasing means normally urging said bar into said first position for supporting said arm on said flat surface;

a member having a series of stops and carried by said structure so as to normally interpose said stops in the path of said back rest arm for holding said head end in a raised position;

means for rendering said biasing means ineffective and holding said bar in said second position so that said arm engages one of said stops and is held in said raised position; and

means for releasing said holding means to enable said biasing means to be effective upon raising of the head end of the back rest so that said arm moves along said fiat surface as said head end is raised or lowered with an operators two hands on said back rest.

I I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; r I 80.0, 338 I Dated April 2, 1974 Inventor(5) J.-

It is certified that error appears in the above-identified patent and that saidLetters Parent are hereby corrected as shown below:

In The s peoification:

Column 2, line 20,"" In operation, assembing" should read In operationres su ming Q 2 line 31, "its being pulled inwardly while th" should read it sbeing pulled inwardly while the Signed and sealed this 27th day of A ug ust 1974.

[SHALL Attest z y MCCOY M. GIBSON, JR. C. ALL DANN Attesting Officer Commissioner of Patents RM P v v I I uscoMM-Dc scam-ps9 Q [1.5. GOYERNMENT PRINTING OFFICE Z 1959 356-334 

1. A body supporting device including a horizontally hinged portion, supporTing means pivotally engaging said hinged portion, at least one relatively fixed stop for holding the supporting means in a position such that the hinged portion is in an elevated position, release means movable between selected positions respectively permitting and preventing engagement of the supporting means with the stop, means normally effective for biasing said release means toward said engagement-preventing position and releasable means for overriding said biasing means and normally holding the release means in said engagementpermitting position.
 2. A body supporting device according to claim 1 in which the supporting means is a strut and there are a plurality of said stops for holding the strut in a plurality of positions, and in which the release means is elongated and in said engagement-permitting position permits engagement of the strut with any selected stop and, in said engagement-preventing position, prevents engagement of the strut with all of the stops.
 3. A body supporting device according to claim 1 in which there are a plurality of stops constituted by pairs of serrations in the sides of a fixed upwardly open channel, in which the release means is an elongated member longitudinally movable in said channel, and which includes cam elements in the form of lugs and grooves interconnecting said release means with said channel so that upon release of said overriding means said biasing means is effective to move said member longitudinally in a first direction to prevent the engagement of said supporting means with all of said serrations.
 4. A body supporting device according to claim 3 in which the biasing means is a spring under tension.
 5. A body supporting device according to claim 2 in which the biasing means is a spring under tension urging the release means toward the engagement-prevention position thereof, and the releasable means is a manually operable latch operable to hold the release means in its engagement-permitting position.
 6. A body supporting device comprising a main frame, a back rest horizontally hinged to said main frame, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and a head end thereof, at least one upwardly projecting stop engageable with the strut, a bar having a generally horizontal surface movable into a position between said strut and said stop to prevent engagement of the strut with the stop, means for biasing said bar into said position and a manually releasable latch for holding the bar out of said position and selectively releasing said bar for movement into said position so that upon lowering of the position of the back rest said strut slides along said bar out of engagement with said stop.
 7. A device for supporting a body in a plurality of positions, one of said positions being generally horizontal, said device being according to claim 1, in which said supporting means is movable into a given plane defined by the hinged portion when said hinged portion is in a first position for supporting said body in said horizontal position, said supporting means in said given plane being effective to override said biasing means and condition said releasable means for overriding the biasing means upon movement of said hinged means out of said first position.
 8. A body supporting device having a main frame and including a horizontally hinged back rest, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and the head end thereof, a plurality of upwardly projecting stops constituted by pairs of serrations in the sides of an upwardly open channel fixed to the head end of the main frame, said stops being engageable with the bottom of the strut and fixed to the main frame at a point corresponding with an elevated position of the back rest, release means including an elongated member longitudinally moveable in said channel, said member being moveable between positions permitting and preventing engagement of the strut with the stops, means for biasing said release means toward said engagement-preventing position, releasable means adapted to hold the release means in said engagement-permitting position, and cam elements interconnecting said release means with said channel.
 9. A body supporting device according to claim 8 in which the cam elements are laterally disposed lugs and slots which are angled away from horizontal, the lugs being engaged in the slots.
 10. A body supporting device according to claim 8 in which the cam elements are lugs projecting laterally from the release means and slots in the sides of the channel, the slots being angled upwardly in the direction away from the head end of the frame and the lugs being engaged in the slots.
 11. A release mechanism for an arm of a back rest of a body supporting structure, said back rest being hingedly connected at one end thereof to said structure and having an opposite end facing the head of said structure, said mechanism comprising: a bar having a flat surface, said bar being movable relative to said structure into first and second positions; biasing means normally urging said bar into said first position for supporting said arm on said flat surface; a member having a series of stops and carried by said structure so as to normally interpose said stops in the path of said back rest arm for holding said head end in a raised position; means for rendering said biasing means ineffective and holding said bar in said second position so that said arm engages one of said stops and is held in said raised position; and means for releasing said holding means to enable said biasing means to be effective upon raising of the head end of the back rest so that said arm moves along said flat surface as said head end is raised or lowered with an operator''s two hands on said back rest. 